SmartVoice Gateway(s) User Guide
85
YML832 Rev1
DHCP relay
Dynamic Host Configuration Protocol relay. A DHCP relay is a computer that
forwards DHCP data between computers that request IP addresses and the DHCP
server that assigns the addresses. Each of the My ADSL Modem’s interfaces can
be configured as a DHCP relay. See DHCP.
DHCP server
Dynamic Host Configuration Protocol server. A DHCP server is a computer that is
responsible for assigning IP addresses to the computers on a LAN. See DHCP.
digital
Of data, having a form based on discrete values expressed as binary numbers (0’s
and 1’s). The data component in DSL is a digital signal. See also analog.
DNS
Domain Name System. The DNS maps domain names into IP addresses. DNS
information is distributed hierarchically throughout the Internet among computers
called DNS servers. When you start to access a web site, a DNS server looks up
the requested domain name to find its corresponding IP address. If the DNS server
cannot find the IP address, it communicates with higher-level DNS servers to
determine the IP address. See also domain name.
domain name
A domain name is a user-friendly name used in place of its associated IP address.
For example, www.globespan.net is the domain name associated with IP address
209.191.4.240. Domain names must be unique; their assignment is controlled
by the Internet Corporation for Assigned Names and Numbers (ICANN). Domain
names are a key element of URLs, which identify a specific file at a web site, e.g.,
http://www.netcomm.com.au. See also DNS.
download
To transfer data in the downstream direction, i.e., from the Internet to the user.
DSL
Digital Subscriber Line A technology that allows both digital data and analog voice
signals to travel over existing copper telephone lines.
Ethernet
Local area network traffic will be carried by standard Category 5 cable referred to
as Ethernet. The most commonly installed computer network technology, usually
using twisted pair wiring. Ethernet data rates are 10 Mbps and 100 Mbps. See also
BASE-T,100BASE-T, twisted pair.
Filtering
To screen out selected types of data, based on filtering rules. Filtering can be ap-
plied in one direction (upstream or down stream), or in both directions.
filtering rule
A rule that specifies what kinds of data a routing device will accept and/or reject.
Filtering rules are defined to operate on an interface (or multiple interfaces) and in
a particular direction (upstream, downstream, or both).
Firewall
Any method of protecting a computer or LAN connected to the Internet from intru-
sion or attack from the outside. Some firewall protection can be provided by packet
filtering and Network Address Translation services.
FTP
File Transfer Protocol - A program used to transfer files between computers con-
nected to the Internet. Common uses include uploading new or updated files to a
web server, and downloading files from a web server.
GGP
Gateway to Gateway Protocol. An Internet protocol that specifies how gateway rout-
ers communicate with each other.
Gbps
Abbreviation for Gigabits (GIG-uh-bits) per second, or one billion bits per second.
Internet data rates are often expressed in Gbps.
GRE
Generic Routing Encapsulation. TCP/IP protocol suite, transport layer encapsulation
protocol.
